Sprint distance measurement

[DJM]

BOF Rules specifically state that

At urban and sprint events the course length shall be given as that of the route from the start via the controls to the finish as shown by the line on the map.

However, the IOF has it differently:

“Sprint Distance measurement
Rule 16.3 states that “The course lengths shall be given as the length of the straight line from the start via the controls to the finish deviating for, and only for, physically impassable obstructions (high fences, lakes, impassable cliffs etc.), prohibited areas and marked routes.”
Of course in urban terrain, there are a lot of impassable obstructions and the shortest route that the runner can take may be twice as long as the direct line. Course planning software will tend to give the direct line distance and often that is quoted as the course length. However, that is incorrect and you should ensure that the correct distance is given.”

What are the pros and cons of each method?

[Gonzo]

Am I misunderstanding? Those two descriptions sound the same to me.

[mikey]

I would have thought that the latter guideline is virtually impossible to measure if you have to take acount of very forbidden boundary/area.

A quick look at WOC 2011 sprint courses suggests that were measured by the straight line route without deviation. I can't believe anyone would expect anything different.

[229]

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[graeme]

229 has it spot on. Method 2 involves a lot of extra work for no benefit.

Bit harsh to single out the JK for being too short, I believe they had it right but lost access for the first section of the course at a late stage.

Related Question: If the BEOC long is won in 84, and our top runners are 30min down at WOC, was it 6 or 36 mins short?

[NeilC]

Also can see no reason for it for sprints where the winning time is known. For Urban races it may be useful to give an indication of actual length (eg 40% more than linear). Of course some planners will quote both staight line and actual distances as well as EWTs in advance and then wait to be shot down
http://www.brightoncityrace.org.uk/

[SJC]

I would have thought that the latter guideline is virtually impossible to measure if you have to take acount of very forbidden boundary/area.

Not impossible, but a large amount of extra work that most planners will not bother with despite what any rules might say.

[229]

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[graeme]

the BOF guidelines for EWT is based upon to British Athletes (or words to that effect), e.g what time would Scott or GG do (previously Jamie or JD), not Thierry or Hubman.

So if Thierry became British in March, we'd have to add a couple of km to BEOC and (since other courses are scaled from M21E) even the W75 courses would get 15% longer just because some bloke got a new passport?

Not saying you're wrong, but that is a bit weird...

[DJM]

A quick look at WOC 2011 sprint courses suggests that were measured by the straight line route without deviation.

The IOF instruction/clarification was issued after WOC 2011 was over - I guess because few, up till then, had spotted what the offical measurement should be!

Not impossible, but a large amount of extra work that most planners will not bother with despite what any rules might say.

But don't planners, in their mind's eye at least, work out optimal routes for each course they produce? How much of a step is it then to use, say, OCAD's Connection Line tool to draw a single zigzag line along this route, then using the Measure tool to find it's length at the selected scale?

CONDES can do something similar I think.

This would then solve the dilemma of planners having a suite of courses to plan, for the JK Sprint, say. These all need to have a consistent winning time, and course length ratio tables are provided to help achieve this. But, if course A has an optimal length of 40% longer than straight line, and course B is only 25% longer, then the ratios are meaningless if applied to the "BOF lengths", but are absolutely pertinent for "IOF lengths" ...

[Arnold]

Quite right that distances should be irrelevant in races determined by winning times.

To me all they're saying is "this terrain is very rough" (short distance, lots of climb) or "there must be lots of uncrossable obstacles in the way" (2k sprint course).
Or of course occasionally "I'm sure they've got that one wrong"! (Lately typically too short though occasionally too long like the recent November Classic).

Re the question of whose winning time it should be, if I remember the BOF guideline is "a top M21 orienteer" for Elite not "the best orienteer in the world". So there's a bit of guesswork involved but I would plan the winning time for a decent run by a top 5 current UK orienteer whether or not they'll actually show up. So if all of them show up and have amazing runs (or Thierry becomes English) then a slightly short winning time is OK. But if a good-but-not-fantastic runner, with an average run, wins in a short winning time then it's not.
Typically this question is only relevant for the long anyway as the "winning window" of 90-95 is pretty small at 5%. For sprint (12-15) and middle (30-35) the windows are much larger so should be easier to hit.

Of course for races where there are no fixed winning times (colour codeds, army events, urban races etc) distances are important, ideally before you enter so you know what you're getting into..

And back to the original question - no way would I spend all that time to measure around obstacles...

[EddieH]

The rules for ISOM maps say that we must measure around uncrossable objects. I always used to do so even though the effect was marginal. Few people ever did I think, and since Condes measures things for me I have stopped doing so.

I personally believe that giving climb is pointless. The figure that different figures that perfectly respectable planners come up with vary so much that it is often irrelevant.

Once you get into sand dunes (this year's JK) the real climb is almost certainly massively more than a map measured figure as you are constantly going up and down.

I NEVER take any notice of the climb figure, but I do of either terrain knowledge, or description if I have no idea.

Of course there are areas where the ground is smooth enough to get a pretty accurate measure. One such the New Forest - it was at a British Champs there where I officially had 315m of climb just a week after a Scottish in Achray where the official climb was 305m.

Whilst the New Forest was bang on, there is no way that Achray could have had less climb but no obvious way of coming up with an accurate figure either.

[NeilC]

How much of a step is it then to use, say, OCAD's Connection Linetool to draw a single zigzag line along this route, then using the Measure tool to find it's length at the selected scale?
CONDES can do something similar I think.

And then manually adjust the distance so that the control descriptions show the right distance and then remember to re-measure and change it when you tweak the courses.....

But, if course A has an optimal length of 40% longer than straight line, and course B is only 25% longer, then the ratios are meaningless

For the Brighton city race courses shamelessly plugged above the ratios all came out between 1.31 and 1.35. I found the same to be true for the two British Sprint Champs that I've officiated in the last few years. Yes there may be some areas where some courses are different to others but that's true for forest events so we just have to trust the planner to compensate. Is there really a problem that needs to be fixed?

[DJM]

I personally believe that giving climb is pointless. The figure that different figures that perfectly respectable planners come up with vary so much that it is often irrelevant.

I'm not keen on threads changing direction, particularly when I'm the one who started the thread in the first place, but I want to make the case for pointfulness of height climb and refute Eddie's case.

It all comes back to course length ratios. A great deal of research has been done into this over the years and it all confirms that you get a better way of comparing one course with another at an event when height climb is included with course length.

It turns out that, provided the height climb has been worked out consistently, course by course, any correction for height climb is better than none, even in sand dune areas.

[graeme]

The two questions are related to each other, just as the various training requirements BOF is bringing in are.

The key point is that all of us have limited time.

Nobody should doubt that measuring actual running distance and measuring climb are better than not doing so. The issue is whether it is so much better that it should be mandated that planners do this task at the inevitable expense of other things.

So for example planning the JK sprint, I could no doubt find out how to use these condes measuring tools, apply, tweak, amend as NeilC suggests. If I did a careful job, I could probably do all that tweaking and checking in 2-3 hours.

2-3 hours would also be sufficient time to test run all the courses.

Which would be more useful?